Battery pack ceramic composite belt and preparation method thereof

Abstract

The invention relates to the technical field of composite belts, and particularly discloses a battery pack ceramic composite belt and a preparation method thereof. The invention relates to a ceramic composite belt for a battery pack. The ceramic composite belt comprises the following materials in parts by weight: 20 parts of alkyl hydrogen polysiloxane; 36 parts of divinyl terminated dimethyl polysiloxane; 15 to 25 parts of filler; 7.5 parts of silicon dioxide; 10 parts of aluminum hydroxide; 3 parts of a catalyst; 1.5 parts of polyurethane modified acrylic resin; 5 parts of polyhydroxy polysiloxane; other 2 parts; the filler comprises ceramic powder and glass fibers; the preparation method comprises the following steps: S1, preparing a base material; s2, stirring for the first time; s3, carrying out secondary stirring; and S4, preparing a composite belt finished product. The ceramic composite belt can be used in the battery pack, and has the advantages of high strength, excellent high temperature resistance and the like.

Description

Technical Field

[0001] The present application relates to the technical field of composite tapes, and more specifically, to a ceramic composite tape for battery packs and a preparation method thereof. Background Art

[0002] Ceramic composite tape is a thermal runaway protection material. Due to its excellent electrical insulation, flame retardancy, high and low temperature resistance, aging resistance, water resistance and corrosion resistance, it is widely used in new energy battery packs, rail transit, aerospace, 5G communications and other fields.

[0003] It is primarily composed of silicone rubber and a ceramic filler. This material offers excellent electrical insulation, flame jet resistance, and thermal insulation. It is particularly effective in addressing the thermal runaway phenomenon of new energy batteries, resisting flame impact and rapidly ceramicizing after high-temperature sintering. However, due to poor dispersion of the ceramic filler, it tends to agglomerate within the silicone rubber, resulting in poor high-temperature resistance of the composite tape. Therefore, improvements to the high-temperature resistance of the composite tape are needed. Summary of the Invention

[0004] In order to improve the high temperature resistance of the composite tape, the present application provides a battery pack ceramic composite tape and a preparation method thereof, which adopts the following technical solutions:

[0005] In a first aspect, the present application provides a ceramic composite tape for a battery pack, comprising the following materials in parts by weight:

[0006] 20 parts of alkyl hydrogen polysiloxane;

[0007] 36 parts of bisvinyl-terminated dimethyl polysiloxane;

[0008] 15-25 parts of filler;

[0009] 7.5 parts of silicon dioxide;

[0010] 10 parts of aluminum hydroxide;

[0011] 3 parts of catalyst;

[0012] 1.5 parts of polyurethane modified acrylic resin;

[0013] 5 parts of polyhydroxy polysiloxane;

[0014] 2 other copies;

[0015] The filler includes ceramic powder and glass fiber.

[0016] By adopting the above technical solution, preferably using alkyl hydrogen polysiloxane and bisvinyl-terminated dimethyl polysiloxane as the base material, a silicone rubber can be formed under the catalysis of a catalyst. The silicone rubber has a low thermal conductivity, that is, it has relatively excellent thermal insulation and flame retardant effects, so that the composite tape has relatively excellent thermal insulation and flame retardant effects. Ceramic powder, glass fiber, silica, and aluminum hydroxide are added to the composite tape. The introduction of the fiber structure can also break down the agglomeration of the fillers to a certain extent, thereby greatly improving the dispersion effect of the fillers. In addition, the glass fiber has relatively excellent heat resistance and high strength, and the network structure constructed by the fibers is introduced into the composite tape, so that the composite tape has uniform high-temperature resistance and strength. The combination of ceramic powder, silica, and aluminum hydroxide can enhance the reinforcing effect of the filler on the silicone rubber, stably improve the strength of the composite tape, and promote the vitrification of the ceramic powder at high temperatures to improve the high-temperature resistance of the composite tape.

[0017] Optionally, the glass fiber is thin strips of glass fiber cloth.

[0018] By adopting the above technical solution, the introduction of thin strips of glass fiber cloth is more conducive to the construction of the fiber network skeleton structure in the composite belt.

[0019] Optionally, the glass fiber is prepared as follows: the glass fiber and the purified fiber are immersed in a modification liquid, subjected to heat treatment, washed, filtered, and dried to obtain the glass fiber; wherein the modification liquid includes an ethanol solution of a silane coupling agent.

[0020] By adopting the above-mentioned technical solution, the glass fiber is purified and modified, and the silane coupling agent is used to graft the glass fiber, effectively improving the compatibility and bonding between the glass fiber and the silicone rubber, thereby improving the uniform support of the fiber network in the composite tape. At the same time, the introduction of the silane coupling agent can cause some fillers to adhere to the fiber surface, further reducing the possibility of filler agglomeration and ensuring uniform and sufficient filler filling in the composite tape.

[0021] Optionally, the modified solution further includes tungsten-doped vanadium dioxide.

[0022] By adopting the above technical solution, vanadium dioxide is a typical compound with a polycrystalline structure and excellent phase change function. Tungsten doping of vanadium dioxide causes lattice changes in vanadium dioxide, thereby improving the conductivity and heat release ability of vanadium dioxide, thereby giving vanadium dioxide even better phase change performance. Modifying glass fiber with tungsten doped vanadium dioxide can introduce phase change particles into the fiber network, that is, introduce a phase change network into the composite tape. The thermal conductivity of the composite tape is adjusted according to changes in the external temperature, forming a thermal barrier network in the composite tape, further improving the thermal insulation effect of the composite tape and enhancing the safety of battery packs.

[0023] Optionally, the tungsten-doped vanadium dioxide is a tungsten-doped vanadium dioxide colloidal liquid.

[0024] By adopting the above technical solution and using tungsten-doped vanadium dioxide colloidal liquid to modify the glass fiber, tungsten-doped vanadium dioxide can be wrapped on the surface of the glass fiber, thereby enhancing the mechanical strength of the glass fiber and stably constructing a phase change fiber network, so that the composite tape can obtain excellent thermal barrier effect and high temperature resistance.

[0025] Optionally, the filler further includes any one of zinc borate, silicon carbide or glass powder.

[0026] By adopting the above technical solution, aluminum nitride, silicon carbide or aluminum oxide are all high-performance fillers with excellent mechanical properties and flame retardant and heat-insulating effects, so that the mechanical strength of the composite belt is improved.

[0027] Optionally, the zinc borate is ultrafine zinc borate.

[0028] By adopting the above technical solution, the filling effect of ultrafine zinc borate in the composite belt is better, so that the composite belt obtains excellent heat insulation and flame retardant effects.

[0029] Optionally, the filler further comprises aramid pulp fibers, and the aramid pulp fibers are wrapped with latex.

[0030] By adopting the above technical solution, the aramid pulp fiber has excellent thermal insulation and mechanical strength, and has a large number of fiber filaments, which can achieve a strong bonding effect between the aramid pulp fiber and the silicone rubber. By wrapping the aramid pulp fiber with latex, the strength of the aramid pulp fiber itself and the bonding effect between the fiber filaments and the main fiber can be improved. In other words, the bonding strength between the aramid pulp fiber and the silicone rubber is further improved, the possibility of fiber filament breakage is reduced, and the composite belt has excellent strength and thermal insulation effect.

[0031] Optionally, the aramid pulp fiber is prepared by dispersing the aramid pulp fiber, dipping the aramid pulp fiber in natural latex, taking out the fiber, and drying the fiber to obtain the aramid pulp fiber coated with latex.

[0032] In a second aspect, the present application provides a method for preparing a ceramic composite tape for a battery pack, which adopts the following technical solution:

[0033] A method for preparing a ceramic composite tape for a battery pack comprises the following steps:

[0034] S1. Preparation of base material: knead together 1 / 3 of the mass of divinyl-terminated dimethyl polysiloxane, 1 / 3 of the mass of polyhydroxy polysiloxane, filler, and aluminum hydroxide to obtain a base material;

[0035] S2, primary stirring: mixing 1 / 2 of the mass of the base material, 1 / 3 of the mass of the bisvinyl-terminated dimethyl polysiloxane, 1 / 3 of the mass of the polyhydroxy polysiloxane, the platinum catalyst, and the acetylenic alcohol, and stirring to obtain a primary stirring semi-finished product;

[0036] S3, secondary stirring: 1 / 2 of the base material, 1 / 3 of the bisvinyl-terminated dimethyl polysiloxane, 1 / 3 of the polyhydroxy polysiloxane, and alkyl hydrogen polysiloxane are mixed, and stirred again to obtain a secondary stirring semi-finished product;

[0037] S4. Finished composite tape: The semi-finished product of the first mixing and the semi-finished product of the second mixing are mixed together, calendered and coated, cured at high temperature for a period of time, rolled up, glued on the coils, cut into pieces, slit, punched, packaged and inspected to obtain the composite tape.

[0038] In summary, this application has the following beneficial effects:

[0039] 1. This application utilizes ceramic powder, glass fiber, silica, and aluminum hydroxide added to the composite tape. The introduction of the fiber structure can also, to a certain extent, break down the agglomeration of the fillers, thereby significantly improving the dispersion of the fillers. Furthermore, glass fiber has relatively good heat resistance and high strength, and the introduction of a fiber-constructed network structure into the composite tape enables the composite tape to achieve uniform high-temperature resistance and strength. The combination of ceramic powder, silica, and aluminum hydroxide can enhance the filler's reinforcement effect on silicone rubber, steadily improving the strength of the composite tape. It can also promote the vitrification of the ceramic powder at high temperatures, thereby enhancing the composite tape's high-temperature resistance.

[0040] 2. In this application, tungsten-doped vanadium dioxide is used to modify the glass fiber, which can introduce phase change particles into the fiber network, that is, introduce a phase change network into the composite tape. According to the changes in the external temperature, the thermal conduction effect of the composite tape is adjusted, and a thermal barrier network is formed in the composite tape, thereby further improving the thermal insulation effect of the composite tape and improving the safety of the battery pack.

[0041] 3. The aramid pulp fibers in this application possess excellent thermal insulation, mechanical strength, and a high number of filaments, enabling a strong bond between the aramid pulp fibers and the silicone rubber. By coating the aramid pulp fibers with latex, the strength of the aramid pulp fibers themselves and the bond between the filaments and the main fibers are enhanced. This further improves the bond between the aramid pulp fibers and the silicone rubber, reduces the likelihood of filament breakage, and achieves excellent strength and thermal insulation for the composite tape. DETAILED DESCRIPTION

[0042] The present application is further described in detail below with reference to the embodiments.

[0043] Preparation Example

[0044] Glass fiber preparation example

[0045] Preparation Example 1

[0046] PANOF staple roving was opened to a fluffy state, and an acetone dispersion of PANOF with a solid-liquid ratio of 1:50 was prepared. The dispersion was refluxed at 75°C, washed with acetone three times, filtered, and dried to obtain purified fiber. The purified fiber was immersed in a modifying liquid, the pH was adjusted to 5, heated at 70°C for 2 hours, with a bath ratio of 1:10, washed, filtered, and dried to obtain glass fiber. The modifying liquid included an ethanol solution of a silane coupling agent (silane coupling agent KH750: ethanol: water = 1:10:1).

[0047] Preparation Example of Tungsten-doped Vanadium Dioxide

[0048] Preparation Example 2

[0049] 4 g of oxalic acid was mixed with 140 mL of water to obtain an oxalic acid solution, 2 g of vanadium pentoxide powder was added to the oxalic acid solution, and the mixture was stirred at 50° C. for 20 min. Sodium tungstate (6.0 at %) and 20 mL of urea solution (0.15 mol / L) were added, and the mixture was stirred at 60° C. for 20 min to obtain a reaction solution. The reaction solution was subjected to a hydrothermal reaction at 185° C. for 48 h, centrifuged, and the solid was retained, washed, dried, and annealed at 700° C. for 6 h to obtain tungsten-doped vanadium dioxide.

[0050] Preparation Example of Tungsten-doped Vanadium Dioxide Colloidal Solution

[0051] Preparation Example 3

[0052] The tungsten-doped vanadium dioxide is melted at 800° C. to obtain a molten solution, and the molten solution is poured into distilled water for quenching, stirring, and filtering to obtain a tungsten-doped vanadium dioxide colloidal solution.

[0053] Preparation Example 4

[0054] The PANOF staple roving was opened to a fluffy state, and an acetone dispersion of PANOF with a solid-liquid ratio of 1:50 was prepared. The dispersion was refluxed at 75°C, washed with acetone three times, filtered, and dried to obtain purified fiber. The purified fiber was immersed in a modifying solution, the pH was adjusted to 5, and heated at 70°C for 2 hours with a bath ratio of 1:10. The solution was washed, filtered, and dried to obtain glass fiber. The modifying solution included an ethanol solution of a silane coupling agent and the tungsten-doped vanadium dioxide prepared in Preparation Example 2 (silane coupling agent KH750: ethanol: water: tungsten-doped vanadium dioxide = 1:10:1:2).

[0055] Preparation Example 5

[0056] The PANOF staple roving was opened to a fluffy state, and an acetone dispersion of PANOF with a solid-liquid ratio of 1:50 was prepared. The dispersion was refluxed at 75°C, washed with acetone three times, filtered, and dried to obtain purified fiber. The purified fiber was immersed in a modifying liquid, the pH was adjusted to 5, and heated at 70°C for 2 hours with a bath ratio of 1:10. The fiber was washed, filtered, dried, and then immersed in the tungsten-doped vanadium dioxide colloidal solution prepared in Preparation Example 3, washed, and dried to obtain glass fiber. The modifying liquid included an ethanol solution of a silane coupling agent (silane coupling agent KH750: ethanol: water = 1:10:1).

[0057] Aramid pulp fiber preparation example

[0058] Preparation Example 6

[0059] Aramid pulp fibers were dispersed and immersed in natural rubber latex with a solid content twice that of the original. The fibers were taken out and dried at 80° C. to obtain aramid pulp fibers coated with latex.

[0060] Example

[0061] Examples 1-3

[0062] On the one hand, the present application provides a battery pack ceramic composite tape, comprising the following materials: alkyl hydrogen polysiloxane; divinyl terminated dimethyl polysiloxane; filler; silicon dioxide; aluminum hydroxide; catalyst; polyurethane modified acrylic resin; polyhydroxy polysiloxane and others, the specific mass is shown in the table below. Among them, the filler includes ceramic powder and glass fiber

[0063] On the other hand, the present application provides a method for preparing a ceramic composite tape for a battery pack, comprising the following steps:

[0064] S1. Preparation of base material: preliminarily mix the filler, then knead together 1 / 3 of the mass of bisvinyl-terminated dimethyl polysiloxane, 1 / 3 of the mass of polyhydroxy polysiloxane, the filler, and aluminum hydroxide to obtain a base material;

[0065] S2, primary stirring: mixing 1 / 2 of the mass of the base material, 1 / 3 of the mass of the bisvinyl-terminated dimethyl polysiloxane, 1 / 3 of the mass of the polyhydroxy polysiloxane, the platinum catalyst, and the acetylenic alcohol, and stirring to obtain a primary stirring semi-finished product;

[0066] S3, secondary stirring: 1 / 2 of the base material, 1 / 3 of the bisvinyl-terminated dimethyl polysiloxane, 1 / 3 of the polyhydroxy polysiloxane, and alkyl hydrogen polysiloxane are mixed, and stirred again to obtain a secondary stirring semi-finished product;

[0067] S4. Finished composite tape: The semi-finished product of the first mixing and the semi-finished product of the second mixing are mixed together, calendered and coated, cured at high temperature for a period of time, rolled up, glued on the coils, cut into pieces, slit, punched, packaged and inspected to obtain the composite tape.

[0068] Among them, hydrogen polysiloxane, bisvinyl-terminated dimethyl polysiloxane, and polyhydroxy polysiloxane are all Dow Chemical materials, silica is from Evonik; the catalyst is from Suzhou Belit Polymer Materials Co., Ltd., aluminum hydroxide is from China Aluminum Shandong Branch; the filler is from Changzhou Panshi Chemical Co., Ltd.

[0069] Table 1 Composition of Examples 1-3

[0070]

[0071]

[0072] Example 4

[0073] The difference from Example 3 is that in this example, the glass fiber prepared in Preparation Example 1 of equal mass is used to replace the glass fiber in the example to prepare the composite tape.

[0074] Example 5

[0075] The difference from Example 3 is that in this example, the glass fiber prepared in Preparation Example 4 of equal mass is used to replace the glass fiber in the example to prepare the composite tape.

[0076] Example 6

[0077] The difference from Example 3 is that in this example, the glass fiber prepared in Preparation Example 5 of equal mass is used to replace the glass fiber in the example to prepare the composite tape.

[0078] Example 7

[0079] The difference from Example 3 is that the filler in this embodiment includes ceramic powder, the glass fiber prepared in Preparation Example 4, and ultrafine zinc borate in a mass ratio of 18:5:2.

[0080] Example 8

[0081] The difference from Example 3 is that the filler in this embodiment includes ceramic powder, glass fiber prepared in Preparation Example 4, aramid pulp fiber and zinc borate in a mass ratio of 18:4:1:2.

[0082] Example 9

[0083] The difference from Example 3 is that the filler in this example includes ceramic powder in a mass ratio of 18:4:1:2, the glass fiber prepared in Preparation Example 4, the aramid pulp fiber prepared in Preparation Example 7, and zinc borate.

[0084] Example 10

[0085] The difference from Example 3 is that the glass fiber in this embodiment is a thin strip of glass fiber cloth, and the width of the glass fiber cloth is 50 μm.

[0086] Comparative Example

[0087] Comparative Example 1

[0088] The difference between this comparative example and Example 3 is that the filler in this comparative example only includes ceramic powder.

[0089] Comparative Example 2

[0090] The difference between this comparative example and Example 3 is that the filler in this comparative example includes ceramic powder and aramid pulp fiber in a mass ratio of 4:1.

[0091] Performance testing

[0092] (1) Thermal conductivity test: Tested in accordance with ASTM E1461.

[0093] (2) Mechanical properties test: The tensile strength of the composite tape was tested using a universal material testing machine in accordance with GB / T528-2009.

[0094] (3) Latent heat of phase change: DSC, heating rate 10°C / min.

[0095] Table 2 Performance test

[0096]

[0097]

[0098] Combining the performance test comparison in Table 2, we can find that:

[0099] 1. Comparison of Examples 1-3 with Comparative Examples 1-2 reveals that the tensile strength of the composite tapes prepared in Examples 1-3 is improved, while the thermal conductivity is decreased. This demonstrates that the ceramic powder, glass fiber, silica, and aluminum hydroxide employed in the present invention are incorporated into the composite tapes. The introduction of the fiber structure can also, to a certain extent, break down the agglomeration of the fillers, thereby significantly improving the dispersion of the fillers. Furthermore, the glass fiber exhibits excellent heat resistance and high strength, and the introduction of a fiber-constructed network structure into the composite tape provides the composite tape with uniform high-temperature resistance and strength. The combination of ceramic powder, silica, and aluminum hydroxide can also promote the vitrification of the ceramic powder at high temperatures, thereby enhancing the high-temperature resistance of the composite tape.

[0100] 2. By comparing Example 4 with Example 3, it can be found that the tensile strength of the composite tape prepared in Example 4 is improved and the thermal conductivity is decreased. This shows that the use of silane coupling agent to graft modify the glass fiber in this application can effectively improve the compatibility and bonding effect between the glass fiber and silicone rubber, thereby improving the uniform support effect of the fiber network in the composite tape.

[0101] 3. Comparison of Examples 5-6 with Example 3 reveals that the tensile strength of the composite tapes produced in Examples 5-6 is improved, while the thermal conductivity is reduced. This demonstrates that the modification of glass fibers by tungsten-doped vanadium dioxide in this application allows the introduction of phase-change particles into the fiber network. This, in turn, introduces a phase-change network into the composite tape, adjusting the thermal conductivity of the composite tape according to changes in the external temperature. This forms a thermal barrier network within the composite tape, further enhancing the thermal insulation of the composite tape and improving the safety of the battery pack. The tungsten-doped vanadium dioxide colloidal liquid is used to coat the surface of the glass fiber, enhancing its mechanical strength and stably constructing a phase-change fiber network.

[0102] 4. Comparison of Examples 8-10 with Example 3 reveals that the composite tapes produced in Examples 8-10 exhibit improved tensile strength and decreased thermal conductivity. This demonstrates that coating the aramid pulp fibers with latex enhances the strength of the aramid pulp fibers themselves and the bonding between the fiber filaments and the main fibers. This further enhances the bonding strength between the aramid pulp fibers and the silicone rubber, reduces the likelihood of fiber filament breakage, and achieves excellent strength and thermal insulation for the composite tapes. Furthermore, the introduction of thin strips of glass fiber cloth further facilitates the construction of a fiber network skeleton structure within the composite tapes.

[0103] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. A ceramic composite tape for a battery pack, characterized in that: The following materials are included in parts by weight: 20 parts of alkyl hydrogen polysiloxane; 36 parts of bisvinyl-terminated dimethyl polysiloxane; 15-25 parts of filler; 7.5 parts of silicon dioxide; 10 parts of aluminum hydroxide; 3 parts of catalyst; 1.5 parts of polyurethane modified acrylic resin; 5 parts of polyhydroxy polysiloxane; 2 other copies; The filler includes ceramic powder and glass fiber.

2. The ceramic composite tape for battery pack according to claim 1, characterized in that: The glass fiber is prepared as follows: the glass fiber is immersed in a modification liquid, subjected to heating treatment, washed, filtered, and dried to obtain the glass fiber; wherein the modification liquid comprises an ethanol solution of a silane coupling agent.

3. The ceramic composite tape for battery pack according to claim 2, characterized in that: The modified solution also includes tungsten-doped vanadium dioxide.

4. The ceramic composite tape for battery pack according to claim 3, characterized in that: The tungsten-doped vanadium dioxide is a tungsten-doped vanadium dioxide colloidal liquid.

5. The ceramic composite tape for battery pack according to claim 3, characterized in that: The filler further comprises any one of zinc borate, silicon carbide or glass powder.

6. The ceramic composite tape for battery pack according to claim 5, characterized in that: The zinc borate is ultrafine zinc borate.

7. The ceramic composite tape for battery pack according to claim 1, characterized in that: The filler further comprises aramid pulp fibers, and the aramid pulp fibers are wrapped with latex.

8. The ceramic composite tape for battery pack according to claim 7, characterized in that: The preparation method of the aramid pulp fiber is as follows: the aramid pulp fiber is dispersed, immersed in natural latex, the fiber is taken out, and dried to obtain the aramid pulp fiber wrapped with latex.

9. The method for preparing a ceramic composite tape for a battery pack according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Preparation of base material: knead together 1 / 3 of the mass of bisvinyl-terminated dimethyl polysiloxane, 1 / 3 of the mass of polyhydroxy polysiloxane, filler, and aluminum hydroxide to obtain a base material; S2, primary stirring: mixing 1 / 2 of the mass of the base material, 1 / 3 of the mass of the bisvinyl-terminated dimethyl polysiloxane, 1 / 3 of the mass of the polyhydroxy polysiloxane, the platinum catalyst, and the acetylenic alcohol, and stirring to obtain a primary stirring semi-finished product; S3, secondary stirring: 1 / 2 of the base material, 1 / 3 of the bisvinyl-terminated dimethyl polysiloxane, 1 / 3 of the polyhydroxy polysiloxane, and alkyl hydrogen polysiloxane are mixed, and stirred again to obtain a secondary stirring semi-finished product; S4. Finished composite tape: The semi-finished product of the first mixing and the semi-finished product of the second mixing are mixed together, calendered and coated, cured at high temperature for a period of time, rolled up, glued on the coils, cut into pieces, slit, punched, packaged and inspected to obtain the composite tape.

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